The present invention relates to a sample processing apparatus and method and device manufacturing method and, more particularly, to a sample processing apparatus and method and device manufacturing method, which process a sample such as a wafer in a predetermined atmosphere such as a reduced-pressure atmosphere of a specific gas and are suitable for an X-ray exposure apparatus, an F2 exposure apparatus, a CVD apparatus, and the like.
As an example of a processing apparatus for processing a substrate in a predetermined atmosphere such as a reduced-pressure atmosphere, an X-ray exposure apparatus for transferring a pattern formed on a mask onto a wafer in reduced-pressure helium atmosphere is known (Japanese Patent-Laid Open No. 2-100311).
FIG. 7 is a view showing a conventional semiconductor manufacturing apparatus. This apparatus uses, as exposure light, SR light, i.e., synchrotron radiation (synchrotron radiation) as soft X-rays and comprises an SR light source 101 for generating the SR light, a beam line 102, and a hermetic process chamber 103. The beam line 102 having an ultra-high vacuum atmosphere is connected to the SR light source 101 through a gate valve 102a to guide SR light to the process chamber 103.
A mask M0 with a transfer pattern formed on a thin membrane and a wafer W0 are placed in the process chamber 103. The mask M0 and wafer W0 are placed on alignment stages (not shown), respectively. At the time of exposure in which the pattern formed on the mask M0 is transferred onto the wafer W0, a helium atmosphere at a reduced pressure of, e.g., 150 Torr is set in the process chamber 103 to suppress any attenuation of the SR light as exposure light.
The process chamber 103 has an X-ray window 104 which is normally made of beryllium. The X-ray window 104 serves as a partition for separating the helium atmosphere in the process chamber 103 from the ultra-high vacuum atmosphere in the beam line 102.
In such a processing apparatus, if the entire process chamber 103 is opened to outer air every time the mask M0 or wafer W0 is loaded to or unloaded from the process chamber 103, a considerably long time is required to open the process chamber to outer air and set the predetermined atmosphere. This reduces the throughput. To avoid this problem, a small load-lock chamber 105 is arranged next to the process chamber 103 such that the mask M0 or wafer W0 is loaded/unloaded to/from the process chamber 103 through the load-lock chamber 105. The load-lock chamber 105 has a gate valve 106 on the process chamber side and a gate valve 107 on the outer air side.
The apparatus also has a coater/developer 108 for applying a resist onto the wafer and developing the wafer after exposure, and a transfer mechanism 109 inserted between the load-lock chamber 105 and the coater/developer 108 to transfer the wafer.
The procedure of loading the wafer W0 to the process chamber 103 will be described below.
(STEP 1) The gate valve 107 on the outer air side is opened, and the wafer is fed to the load-lock chamber 105 by the transfer mechanism 109. At this time, the gate valve 106 on the process chamber 103 side is kept closed.
(STEP 2) The gate valve 107 on the outer air side is closed, and a reduced-pressure helium atmosphere is set in the load-lock chamber 105.
(STEP 3) The gate valve 106 on the process chamber 103 side is opened, and the wafer W0 is transferred into the process chamber 103 by a transfer mechanism (not shown) in the process chamber 103.
For unloading, the procedures are reversed.
In the conventional semiconductor manufacturing process, the whole manufacturing apparatus is installed in a clean room of a factory, thereby taking a measure against contamination by dust or the like. However, for micropatterning of 0.2- to 0.1-xcexcm level coping with recent semiconductor integration, the required cleanliness becomes strict from class 10 to class 1. To achieve this cleanliness in the entire clean room, the clean room building/maintenance cost becomes incredibly high. In addition, maintenance of one apparatus decreases the cleanliness in the entire clean room, resulting in adverse effect on other apparatuses.
As described above, the processing apparatus requires a load-lock chamber to improve the throughput. Since the load-lock chamber atmosphere changes from outer air to the same atmosphere as in the process chamber 103 and vice versa, the cleanliness must be managed depending on the atmosphere.
The present invention has been made in consideration of the above conventional problems, which are kept unsolved, and has as its object to provide a processing apparatus and method and a device manufacturing method which can inexpensively manage the cleanliness throughout the transfer path for a sample such as a substrate and effectively avoid contamination of the sample.
It is the second object of the present invention to manage the cleanliness throughout the sample transfer path and efficiently manage the cleanliness in the load-lock chamber at the time of loading/unloading a sample.
It is the third object of the present invention to manage the cleanliness throughout the sample transfer path and easily manage the cleanliness in the load-lock chamber depending on the atmosphere.
It is the fourth object of the present invention to manage the cleanliness throughout the sample transfer path and manage the cleanliness in the load-lock chamber depending on the atmosphere while suppressing moisture mixing.
The first aspect of the present invention is related to a processing apparatus for processing a sample. The processing apparatus comprises a process chamber for processing the sample in a predetermined atmosphere, a load-lock chamber connected to the process chamber, a transfer mechanism for transferring the sample between the load-lock chamber and another unit or container, a clean booth which covers a transfer path of the transfer mechanism, and a transfer atmosphere forming mechanism for flowing a clean gas in the clean booth.
According to a preferred embodiment of the present invention, the transfer atmosphere forming mechanism preferably comprises, e.g., a supply source of the gas, and a filter inserted between the supply source of the gas and the transfer path, and more preferably, further comprises a straightening plate for passing the gas from the filter, which has passed through the transfer path.
According to a preferred embodiment of the present invention, the processing apparatus preferably further comprises, in the load-lock chamber, a gas control mechanism for supplying a clean gas which is the same as in the process chamber or as in the clean booth into the load-lock chamber or exhausting the gas from the load-lock chamber. To supply the gas which is the same as in the process chamber to the load-lock chamber, the gas control mechanism supplies, e.g., the clean gas in the process chamber to the load-lock chamber, and to supply the gas which is the same as in the clean booth to the load-lock chamber, the gas control mechanism supplies, e.g., the clean gas in the clean booth to the load-lock chamber. More preferably, gates are arranged between the load-lock chamber and the process chamber and between the load-lock chamber and the clean booth, in transferring the sample from the load-lock chamber to the process chamber, the gas control mechanism supplies the same clean gas as in the process chamber to the load-lock chamber before the gate between the load-lock chamber and the process chamber is opened, and in transferring the sample from the load-lock chamber to the clean booth, the gas control mechanism supplies the same clean gas as in the clean booth to the load-lock chamber before the gate between the load-lock chamber and the clean booth is opened.
According to a preferred embodiment of the present invention, the processing apparatus preferably further comprises, in the load-lock chamber, a gas control mechanism for supplying a clean gas which is the same as in the process chamber or a clean dry gas into the load-lock chamber or exhausting the gas from the load-lock chamber. More preferably, gates are arranged between the load-lock chamber and the process chamber and between the load-lock chamber and the clean booth, in transferring the sample from the load-lock chamber to the process chamber, the gas control mechanism supplies the same clean gas as in the process chamber to the load-lock chamber before the gate between the load-lock chamber and the process chamber is opened, and in transferring the sample from the load-lock chamber to the clean booth, the gas control mechanism supplies the clean dry gas to the load-lock chamber before the gate between the load-lock chamber and the clean booth is opened.
According to a preferred embodiment of the present invention, the transfer atmosphere forming mechanism forms a laminar flow of the clean gas in the clean booth.
According to a preferred embodiment of the present invention, preferably, the processing apparatus further comprises an exposure apparatus in the process chamber, and another unit comprises a coater/developer.
Another aspect of the present invention is related to a method of processing a sample, comprising the steps of transferring the sample to a load-lock chamber by a transfer mechanism installed in a clean booth in which a clean gas flows, adjusting a pressure in the load-lock chamber and transferring the sample from the load-lock chamber into a process chamber, processing the sample in the process chamber, transferring the sample from the process chamber to the load-lock chamber, and adjusting the pressure in the load-lock chamber, extracting the sample from the load-lock chamber, and transferring the sample by the transfer mechanism installed in the clean booth in which the clean gas flows.
According to still another aspect, the present invention is related to a method of manufacturing a device, comprising the steps of transferring a substrate coated with a photosensitive agent to a load-lock chamber by a transfer mechanism installed in a clean booth in which a clean gas flows, adjusting a pressure in the load-lock chamber and transferring the substrate from the load-jock chamber into a process chamber, transferring a pattern onto the substrate by an exposure apparatus installed in the process chamber, transferring the substrate from the process chamber to the load-lock chamber, adjusting the pressure in the load-lock chamber, extracting the substrate from the load-lock chamber, and transferring the substrate by the transfer mechanism installed in the clean booth in which the clean gas flows.
The preferred embodiment of the present invention solves a problem that if the transfer mechanism for transferring the substrate to be processed from the coater/developer for executing pre-process and post-process of the substrate to be processed to the load-lock chamber is exposed to air in the clean room, the cleanliness in the entire clean room must be increased to maintain the cleanliness of the atmosphere in the process chamber and load-lock chamber, resulting in an increase in cost. According to the preferred embodiment of the present invention, the entire transfer path by the transfer mechanism is arranged in the clean booth, and a laminar flow of a clean gas is formed in the clean booth, thereby preventing dust from sticking to the substrate to be processed.
According to a preferred embodiment of the present invention, the substrate such as a wafer to be processed can be kept in the clean state during transfer only by managing the compact clean booth without increasing the cleanliness in the entire clean room. For this reason, as compared to the case wherein the entire clean room is strictly managed, the cost can be reduced, and the maintenance does not adversely affect other apparatuses.
Providing a load-lock chamber gas fluidizing mechanism (gas control mechanism) for generating a laminar flow of a clean gas in the load-lock chamber in accordance with the preferred embodiment of the present invention is very effective in keeping the substrate to be processed in the load-lock chamber clean.
When the gas control mechanism for selectively supplying the ambient gas in the process chamber or air in the clean booth to the load-lock chamber is arranged in accordance with the preferred embodiment of the present invention so as to circulate the gas, the cost can be further reduced.
When the gas control mechanism for selectively supplying the ambient gas in the process chamber or dry gas to the load-lock chamber is arranged in accordance with the preferred embodiment of the present invention, moisture can be prevented from entering the load-lock chamber to prevent contamination of the substrate to be processed, or the vacuum suction time can be shortened.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.